Multiple-tube expander



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T. J. DIXON.

MULTIPLE TUBE EXPANDER.

FILED DEC. I, 1920. 1,417,979. Patented May 30, 1922.

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IQQII INVENTOR /oma 17 "rrm/ P@ ATToRNEYs "THOMAS J. Dixon, or iviiinrsoii, wisconsin, iissienon To LovrJoY Toon woiaxs, or

f Oirroaeo, immersa coitromirroir or' intinois.

MULTIPLE-TUBE EXPANDEB.

To all whom t 'may con-cern:

Be itflnown that I, THOMAS J. Dixon', a citizen of the United States, residing at Madison, in the county of Dane and State of Visconsin, have invented a new and Improved liultiple'flube Expandeuof which the following is a specification.

My-present invention has reference to improvements to tools more especially adapted for expanding boiler tubes, and primarily it has for 'its Obje'ctfto `provide a tool of the general character. stated, of such improved design and construction that a single tool is provided vwhich may be conveniently and expeditiouslyused,-without any special adjustment of thepartsthereof for expanding a number-of different* sizes of tubes, which is of few parts of simple construction, that can be cheaply niade,is durable and-is capableof easy manipulation forserving its intended purpose. I l

Another obj ect of myl present invention, is to provide an improvedk construction *i of boiler tube expanderlof the general type stated, having thevtubeexpanding elements so arranged.and.adapted forbeing cooperatively applied =upon andy removed vfrom the forward end of the Vexpanding mandrel, which .constitutes a part of the complete tool, andin which is included a simple means for holding the expanding element from freely working off the end of the mandrel and which servesfas an inexpensive and practical substitute for `the stop nut devices usually employed forl suoli-purposes and which, when applied, cannot work ofi' `the end of the mandrel, as is possible yiii-the common type of stop nut which threads onto theinandrel end. l

Vith other'objects in view that will hereinafter be mentioned,fmyinvention is an iniproved boiler ;tube expander, that'embodies the peculiar features of vconstruction `and novel arrangement of;parts, all fof which are fully set forth in the following detailedL 'description, specifically pointed out inthe appended claims and illustrated in the accompanying drawings, in'vwhich:

Figure lis a plan view of aboilertube expander that embodies myv invention.

Figure 2 isa cross section thereof on the line 2-2 on Figure 1, looking in the direction ofthe arrow.' f

Figure 3 is a similar view taken lontlie scribed in detail.

Specification of Letters'IPat'ent. I gmtntd Flay 30,1922

Application ledeceinoer 1, 1920. Serial No. 427,568. l

line 3 3 on Figure il, looking in the direction of the arrow.

Figure 4 is a detail perspective view of the retainer device cooperative with -the vmandrelhand which serves to vprevent-the expanding` roller carrying heads from slippino' olithe front or smaller end ofthe'mandrel- F .igi'ires 5 ando are diagrammatic. cross sectional views ofthe y-niandrel and 4illustrates the normal shapel ofthe retainer element, ywhenapplied uponthe mandrell end, s

vand-the:manner in which the said element is changed in -its shape for being held from passing over `theenlargement-orhead porktionof vthe front end 'of theinandrel'. n

Figure 711s a diagrammatic plan view that illustrates a somewhat modiiedcarrange-f ment of my invention,.as hereinafter de- The 'preferred form' Tof my boiler tube expander, illustrated in Figures l'to 6, compriseszesseiitially atubularfbody, the bore' 2 of which gradually tapers from the rear to the forward end, ywhich bore is large enough `to accommodate the usual lmandrel l.

In the preferred form stated, the body of the tool is composed ofaplurality of stepped hub-lilre portions 3, 4 and 5,1the'outer one (3) beingof the largest diameter, the next f one of a lesser diameter than the-partz, whereby, at thejunctureof the twohuby portions Sand 4L', an annular-stop shoulder G is provided, a. like stop shoulderl 7- being formed on the outer yend of the part 4 by reason of the reduced'diameter ofthe third hub-like portion 5. f

. 8 designates a stopzshoulder or abutment flange which isintegral with the front end `of the hub portion, thereason for which will 'be presently 1 explained.

Each of he body portions 3,-,4C=and is lprovided with a 'series of radially disposed pockets 30, 40 ando() that merge with the bore 2 and which are of progressively reduced sizes, and in each set of the said pockets, that is thethree pockets of the several portions 3, land 5,'are held the ex- 'panding rollers 9 9, which rollers Aand the several pockets in which they are held and adapted for being radially projectedv by the mandrel feed, as will -be presently further explained, are somewhat diagonally disposed with-respect to the longitudinal axis Oftheir respective body or hub portions `and the to seat within their respective pockets by the ff insertion ofthe mandrel l, it being understood that the farther the mandrel is fed forward, the more will the radially disposed sets of expanding rollers be projected beyond the peripheral face of their respective bodyor-hub portions 8, 4 and 5.

To prevent the rollers 9 'from dropping 'out through the radial pockets, in which they areheld for rotation as the expander is fed into the'tube, when the tool is withdrawn from the tube, the outer or peripheral ends of the several pockets are somewhat restricted in their width bythe lip-like ortionsljand 5l, as is clearly shown in *igure's 2 and 3.of the drawings.

' At the outer end, the mandrel 1, in my construction. of expander tool,` has an integral head 10 of suiiicient small diameter to permit of freely passing the mandrel through the'smaller end ll of the bore 2 in the shelly or body ofthe tool.

, In the common types of fiue expanders,

. the outer or smaller end of the tapering mandrel is threaded for the reception of a nut which acts as a retainer to keep the body or head portions that carry the expander rollers from slipping ofi the outer end of the mandrel.

The use of a nut for retaining the parts upon the mandrel is not always reliable, since such nuts frequently work loose from the threaded end of the mandrel.

In my present construction of expander, to insure a positive connection of the mandrel with the shell or body and thereby insure the holding of the expanding rollers in proper place, l provide a simple and inexpensive substitute for the common type of nut retainer,l which is in the nature of a fiat band or ring l2 of sufficient diameter for being freely passed over the mandrel head l0, as indicated in dotted lines on Figure 5.

The band or ring 12 is of flexible metal and, when slipped over the mandrel head, by resting it and the mandrel head on a solid base as indicated in Figures 5 and 6 yand giving the ring or band a tap with a hammer, it is reduced to an oval shape with f its openings so restricted transversely (see alsl Figure 6) that under ordinary conditions of handling the mandrel, the ring or band cannot be slipped therefrom, making it impossible to separate the shell or body and the mandrel without first straightening, or` in other words, rounding the band or ring l2 in the same manner in which itvwas flattened.

So far as described, it will be readily apparent, to those familiar with the use of boiler tube expanders of the type to which my present invention relates, that my improved tool can be readily used for expanding tubes of different standard diameters. When the tool is arranged, as in Figure l, with the several units', i. e, the bodyportions 3, 4, and 5 of different diameters, when, say

pandedby the smallestunit or body portion l, the said body portion, during the opera-v tion of expanding the tube,'is constantly fed forward in the usual manner until the shoulder 7 of the next unit 4 engages the outer end of the tube and thereby limits the further inthrust ofl the unit 5.`l y

The same conditions'are present when a larger diameter tube is being expanded by the unit or body 4 and its rollers, the infeed being limited by the shoulder 6v of the unit y engaging with the end of the largest or outermost expanding unit, and they Ilatter being the last of the series of unitshas the integral annular Harige 8, before referred to, which constitutes the stop for limiting the inthrust or feed of the unit 3y into the y'tube being expanded thereby.

In Figure 7 is illustrated a somewhat t kso the smallest tube, is adapted for being exmodified form of my expander,` and, inthis form7 the parts have the same generaly ar'- r'angement as in F iguresl, 2, and', except that the several units or portions 3, 4 and 5 are in the nature of a plurality of individual bodies or shells, each containing its set vof expanding rollers arranged the same as in the other or preferred form described'.

In this modified form of my invention, l have shown one of the units, the central one, as provided with an integral annular flange llUy 45 which constitutes the tube end abutting y element for limiting' the infeed of the unit and, if desired, all of the individual units shown in Figure 7 may have integral abutment flanges, although for ordinary uses, the end of the next adjacent unit may be utilized as an abutment, the same, as in the integral arrangement shown in Figure 1f.

Mtaking the several units independently shiftable along the mandrel and providing each shiftable unit with an integral abutment flange, has its advantages, since it will be readily apparent that the unit or units not in immediate use, may be slipped back, a couple of inches, out of the; way of the flue sheet and any'rivets cr'other objects projecting therefrom. A Y

In the modified form of my invention, I have shown the' mandrel equipped'with the common type of retainer nut 15 engaging the threaded end of the mandrel.

Vhat I claim is:

l. In a tubev expander, the combination with an expanding unit including a set of radially shiftable expanding rollers, and a mandrel that engages the saidset of rollers and holds them to theiroperative position, the said mandrel having an annular enlargement or head at the forward end; of a ring of flexible metal adapted for being slipped onto the mandrel over the head, and for being compressed around the mandrel to constitute a retainer to prevent the separation of the mandrel and the expanding unit.

2. In an expander of the character described, the combination With a tapering headed end of the mandrel can pass, the

said unit having a plurality of radial pockets from its bore through its peripheral face, expander rollers adapted for being placed through the axial bore in the expanding unit into their respective radial pockets and shiftable to their expandedv adjustments by the mandrel andan elongated ring on the outer end of the mandrel adapted for engaging with vthe head of said mandrel and Which operates to hold the mandrel and the expanding unit thereon from disconnection.

THOMAS J. Dixon. 

